Cod sursa(job #2945121)
Utilizator | Caplea Alexandru mrajecu | Data | 23 noiembrie 2022 14:52:15 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.53 kb |
#include<iostream>
#include<fstream>
#include<math.h>
using namespace std;
int ciur[2000001];
long ciurul(long n)
{
long count=0;
for(long i = 2; i <= n; i++) {
if(ciur[i] == 0) {
for(long j = 2 * i; j <= n; j =j + i) {
ciur[j] = 1;
}
}
}
for(long i = 2; i <= n; i++)
if(ciur[i]==0)
count++;
return count;
}
int main()
{ long n;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
fout<<ciurul(n);
return 0;
}